Door stop construction



Oct. 23,1956 v. K. FREMSTAD 2,757,421

DOOR STOP CONSTRUCTION Filed Jan. 10,v 1955 xii? IN V EN TOR.

DOOR STOP CONSTRUCTION Viles K. Fremstad, Van Nuys, Calif., assignor toAjax Hardware Manufacturing Corporation, Los Angeles, Calif., acorporation of California Application January 10, 1955, Serial No.482,320 4 Claims. (Cl. 16-85) The present invention relates generally tobuilders hardware, and more particularly to door stops having flexibleshanks.

Door stops of this character are designed to be attached to the base ofa vertical wall in order to receive the impact from the door swingingback. against the wall and thus protect the wall, as well as the door,from damage. Door stops for this been well known for a long time.However, they have suffered from the great disadvantage that the rigidstop did not yield when struck from the side. When a vacuum sweeper or amop or other cleaning'instrument hit the door stop with suflicientforce, either the shank was broken or the door step as a whole was tornoff from the face of the wall. Repeated injury to or loss of door stopsfrom this cause has frequently resulted in failure to replace them withthe consequent loss of the protection that they afford.

In order to remedy this situation, door stops with flexible shanks havebeen devised. These are designed to yield under laterally applied blowsand then return to their normal position. Known designs of flexible doorstops succeed in this objective only to a certain extent, because whenthe blow is applied close to the base of the door stop, the flexibleshank is bent so sharply that it takes a permanent set and fails toreturn to its normal position. Once the door stop :has been defonmedsulficiently to no longer return to its normal position, it is often asuseless as if it had been broken or torn oflf the wall.

Hence it is a general object of my invention to provide an improveddesign for a door stop having a flexible shank which will insure that ityields to all lateral blows and then will return to its normal position.

It is also an object of my invention to provide an improved design for adoor stop with a flexible shank in which the shank is so designed thatit will deflect sharply in the vicinity of its base without taking apermanent set.

These objects of my invention have been achieved in a door stopcomprising a flexible shank of novel design having an impact receivinghead attached to one end of the shank and a base attached to the otherend by which the door stop is mounted on a wall or other supportingmeans. The shank is in the form of a coil spring having a plurality ofsuccessive turns, which, for at least the major portion of the shank,are in engagement with each other. The turns of the coil are not ofuniform diameter throughout the entire length of shank. Rather, theshank is formed with a section intermediate its ends at which the turnsare of maximum diameter. The diameter of the turns decreasesprogressively in either direction away from this point of maximumdiameter and toward the ends of the shank.

In a prefenred construction, the first several turns at one end of theshank are of uniform diameter and engage the base by which the door stopis mounted on its support. Adjoining this section is a section in whichthe purpose having a rigid shank have V 7 7 42 Patented Oct .-23, 1 6-turns increase progressively in diameter away from the base. This may befollowed by another section in which the turns of the successive coilsdecrease in diameter outwardly of the shank.

How the above objects and advantages of my invention, as well as othersnot specifically mentioned herein, are attained will be betterunderstood by reference to the following description and to the annexeddrawing, in which:

Fig. 1 is a perspective view of a door stop constructed according to myinvention, showing the door stop in operating position;

Fig. 2 is a side elevation of it bends in response to a outer end;

Fig. 3 is a similar view on an enlarged scale, partially in verticalmedian section, showing how the door stop deflects in response to aforce applied laterally near the base;

Fig. 4 is a vertical transverse section on Fig. 3; and

Fig. 5 is a side elevation of a variational form of door stop.

Referring now to the drawing, it will be seen that the door stopcomprises three principal portions, a flexible shank 10, a mounting base11 at one end of the shank, and a blow receiving head 12 on the otherend of the shank. Base 10 is of well known construction and includes awood screw 14 which may be screwed into a wall or the like in ordertomount the door stop in the proper position. The mounting base is alsoprovided with a section 15 having a plurality of flat sides which may begripped by a wrench for the purpose of turning the base in order toadvance screw 14 into the support.

Shank 10 is a coil spring which preferably has its successive turns incontact with each other, for at least a major portion of its length, inorder to give desirable rigidity to the shank to resist endwise blows.Being a spring, it yields, as shown in Fig. 2, to laterally directedblows applied at or near the outer end, as represented by arrow 16.

At the inner or base end, the shank has an initial section 10acomprising a plurality of turns of uniform diameter. These surround ashort threaded stud 18 which is part of base 11 in order to attach thebase to the shank. Other means of connecting the shank and base togethermay be used if desired.

Adjoining shank section 10a but outwardly therefrom is section 1012 ofthe shank. In this section the diameter of the several turns increasesprogressively outwardly from base 11. The rate of increase is such thatthe turns still keep contact with each other, each turn being largerthan the preceding one by preferably about one-half the diameter of thewire from which the spring is wound. This prevents the turns fromtelescoping when endwise blows are applied to the shank.

The largest diameter of the coils may be continued on as shown in Fig.5, if desired, to the outer end of the shank; but it is preferred toreduce the diameter gradually to about the initial diameter. Hencesection 1% adjoins a section 100, longer than the others, in which thediameter of the several turns gradually decreases, outwardly of theshank, from the maximum value. At the extreme outer end, where head 12is mounted on the shank, the diameter is conveniently the same as at thebase end. This shank design offers a pleasing appearance with itslargest diameter at a position intermediate the ends of the shank andgradually tapering in size toward each end.

As a consequence of this construction, the shank deflects under lateralloads when applied near the base, as

the door stop showing how blow applied laterally at the line 4-4 ofrepresented by the arrow .21) inPig. 2, without taking a pennane'ntset.When the load is applied near the end tu. .8, a ithe def rma i n mustoccur in the shank between the end of the stud and the point ofapplication of the force. Hence most of the deformation takes place inthe short length of section 1%. This section can undergo considerabledeformation. without permanent change of shape. It 'appearsthat thesuccessive turns, because of the progressive change in diameter, areable toslide laterally over one another at the side away from theforceand to spread apart on the near side in a manner to give a sharpbend to the shank as a whole but without concentrationg the bending inany one turn to such a degree as to give it a permanent set. Theprogressive change in diameter of the turns allows them to move morerelative to each other than if they were all the same size. As aconsequence, a shank of my novel design returns toitsnonmal positionrepeatedly after blows that can permanently bend a spring of uniformdiameter.

A variational form of door stop is shown in Fig. 5 which is the same asthat already described except that the diameter of the turns does notdecrease in section 100, the maximum diameter of section 1012 beingcontinued on to the outer end of the shank. When the shank deflectsunder lateral loads, deformation takes place in section 1% as describedabove.

Since various changes can be made in the design of my novel door stopwithout departing from the spirit and scope of my invention, it is to beunderstood that the foregoing description is considered to beillustrative of, rather than limitative upon, the scope of the appendedclaims.

I claim:

1. A door stop comprising a helical spring member fonrning a shank oneend of which is provided with a base 4 member havingan"outwardly;projecting stud portion to which the said end of the shankis secured by engagement :of the co lstherewith, the Qpposi eendof saidshank having an impact receiving head attached thereto, said thank beingprovided intermediate its ends with a portion of increased diameterlying adjacent to out spaced from the outer end of the stud portion ofthe base member.

2. A door stop as claimed in claim 1, wherein the end of said shankhaving an impact receiving head attached thereto is 101': a diametergenerally approximating that of the end thereof engaging 'said studportion.

.3. A. door sto'p asjclaimed. in claim 1, wherein the portion of saidshank ofincreased diameter has its coil portion of greatest diameterlocated adjacent to the outer end of thestud portion: but spacedtherefrom, the said portion of increased diametertapering toward thestud-engaging end portion of the shank.

4. A door stop as claimed in claim 1, wherein the portion of said shankof increased diameter has'its portion of greatest diameter locatedadjacent to the outer end of the stud :portion but: spaced therefrom,the said portion of increased diameter tapering toward both ends of theshank.

'ReferencesCited in the file of this patent UNITED STATES PATENTS1,232,000 Chase July 3, 1917 1,983,784 Watkins et al. Dec. 11, 19342,254,566 Cornell Sept. 2, 1941 2,462,174' Fisher Feb. 22, 19492,700,788 Hennelly Feb. 1, 1955 FOREIGN PATENTS 258,483 Great BritainSept. 23, 192.6

